High resolution mapping and development of diagnostic KASP markers for FHB resistance QTL on chromosome 1B in an elite soft red winter wheat cultivar ‘Jamestown’

Abstract Fusarium Head Blight (FHB) is a serious disease of wheat, causing yield and quality losses to the grain. Genetic resistance is one of the most important strategies to manage FHB. QTL from unadapted genetic backgrounds, such as wild relative species and exotic landraces, have been used in wheat breeding lines across the world. However, deployment of such sources poses problems associated with linkage drag, that impede their quick deployment in cultivars. Previously, we reported mapping of an FHB resistance QTL on chromosome 1B of an elite soft red winter wheat (SRW) cultivar Jamestown using Recombinant Inbred Lines (RIL) populations. In this work, we developed a high-resolution mapping population with 475 individuals by crossing resistant and susceptible RILs. Genome-specific KASP markers were developed and used to genotype the population. Phenotyping, followed by progeny testing of the recombinants, reduced the genetic interval to a 3 Mb region predicted to contain 17 high-confidence genes in the corresponding region in the Chinese Spring reference genome ver 1.0. The KASP marker flanking the 1B QTL region was validated on the SRW breeding germplasm of the Eastern US, which showed improved correlation over the previous markers used for MAS of this QTL. This work will facilitate breeding of 1B_FHB QTL from Jamestown to wheat varieties widely.